The present invention relates to an engine-driven water supply/drainage pump configured to supply/drain water, and more particularly, to a water supply/drainage pump having a function to damp engine noise.
Hitherto, there have been known water supply/drainage pumps configured to be driven by an internal combustion engine. The water supply/drainage pumps are used in various fields such as agriculture and civil engineering, more specifically, irrigation, drainage, water pumping, and the like.
In recent years, in consideration of influence of noise of the engine on a surrounding environment, the possibility of providing a soundproof water supply/drainage pump including a soundproof cover configured to cover the engine and a pump such that leakage of the noise of the engine to an outside is prevented as much as possible has been investigated.
However, when the engine and the pump are covered with the soundproof cover in this way, sufficient ventilation is difficult to perform. As a result, the engine cannot be sufficiently cooled. In contrast, in order to obtain sufficient cooling performance, a large ventilation hole needs to be formed through the soundproof cover. As a result, noise damping performance is degraded.
In order to solve such problems, development of an engine-driven water supply/drainage pump having both a cooling function and a noise damping function has been demanded.
Under such circumstances, as a water supply/drainage pump having both the cooling function and the noise damping function, the inventor of the present application has been proposed a soundproof engine pump disclosed in Japanese Patent Application Laid-open No. 2001-152847.